Metlink bus fleet cuts emissions by a quarter since 2019

Greenhouse gas emissions from Metlink’s bus fleet are 25 per cent lower than in 2019, while nitrogen oxide emissions have fallen by almost half, as the region continues its transition to cleaner buses.

Air quality monitoring by Greater Wellington shows there have also been improvements along Wellington’s Golden Mile, with diesel particulate levels falling 47 per cent since 2021.

Greater Wellington Regional Council Public Transport Committee Chair Ros Connelly said the results showed the progress being made towards a cleaner public transport network.

“Reducing emissions from public transport is important for the region. It’s not just about addressing climate change - cleaner air benefits everyone.

“Diesel exhaust can worsen asthma, affect heart and lung health, and harm children’s lung development. Reducing these pollutants means people living, working and spending time in busy areas like the Golden Mile are exposed to less harmful pollution.

“We’re seeing measurable reductions in emissions from the bus fleet, and we’re continuing to invest in the transition to cleaner vehicles.”

During the 2025/26 financial year, electric buses accounted for 29 per cent of all kilometres travelled by the Metlink bus fleet and the distance travelled by electric buses increased by 6 per cent.

Over the same period, greenhouse gas emissions fell by a further 0.5 per cent and nitrogen oxide emissions by 6 per cent, reversing an upward trend in recent years.

Metlink Group Manager Samantha Gain said replacing older diesel buses with electric and newer, lower-emission vehicles was helping reduce the fleet’s environmental impact.

“Older diesel buses produce a disproportionate share of some harmful emissions. While they make up a relatively small part of the fleet’s total distance travelled, they contribute a much larger share of its nitrogen oxide and particulate emissions.

“Moving to cleaner buses, and progressively retiring older vehicles, is an important part of reducing those emissions.”

The annual report tracks emissions from the Metlink bus fleet and air quality along the Golden Mile, helping monitor progress as the region works towards a cleaner public transport network.

Key facts

• Greenhouse gas emissions from the Metlink bus fleet are 25 per cent lower than in 2019.
• Nitrogen oxide emissions are 49 per cent lower than in 2019.
• Diesel particulate levels monitored along Wellington’s Golden Mile are 47 per cent lower than in 2021.
• Electric buses accounted for 29 per cent of the fleet’s in-service kilometres in 2025/26.
• 122 of the 480 buses in the Metlink fleet are electric